Merge #7935: Versionbits: GBT support
12c708a getblocktemplate: Use version/force mutation to support pre-BIP9 clients (Luke Dashjr)
9879060 getblocktemplate: Explicitly handle the distinction between GBT-affecting softforks vs not (Luke Dashjr)
72cd6b2 qa/rpc-tests: bip9-softforks: Add tests for getblocktemplate versionbits updates (Luke Dashjr)
d3df40e Implement BIP 9 GBT changes (Luke Dashjr)